Automatic steering device



G. c. SAUL ETAL 2,373,144

AUTOMATIC STEERING DEVICE April 10, 1945.

Original Filed June 22, 1938 2 Sheets-Sheet l as M/Z W Al/L, A/PD/IY$, "B 6 BY P. lV/JBET.

T Em ATTORN April 1945- G. c. SAUL ET AL AUTOMATIC STEERING DEVICE .Original Filed June 22, 1938 '2 Sheets-Sheet 2 B I? Iii-3E7: THEIR ATTORN Y- Patented Apr. 1945 UNITED STATES PATENT OFFICE AUTOMATIC'STEERING DEVICE George Cecil Saul, Beckenham, William George Harding, Whitton and Robert l layes Nisbet,

} Stroud, England, assignors to Sperry Gyroscope- Company,'lnc., Brooklyn, N. Y., a'corporatlon .of New York Continuation of application semi N... 215,282, June 22, 1938. This application October 14, 1941, Serial No. 414,930. In Great Britain June .1 g 6Claims. (cure-28w This invention relates to automatic steering systems-for ships, that is, particularly concerned with the provision of meansfor suppressing the yaw of automatically steered ships. We have shown our invention as applied to a Ward- Leonard electrical system of ship steering but it will be obvious from the following description I that it is. also applicable to other types of auto-.

thus imparting a relative movement between the trolley and contact ring. in addition to the movement which is proportional to the angular matic steering gear, such as shown in Sperry Patent 1,695,615, for Automatic steering for ll dirigible craft, dBfied December 18, 1928. By using "a WardrLeonard system with balanced potentiometersat the automatic pilot and rudder, we avoid the use-of mechanical follow-back con- 7 nections from the rudder to the pilot house, as

shown insaidpatent, and thereforehave not shown the usual lost motion connection in such follow-back connection for effecting the sup- ,pressionof ships yaw. In order to accomplish this purpose, we do not mereLv operate the con- -.tro1ler proportionally to the angular displace- .ment of the change from course or in other words proportional to the movement of the compass repeater motor, but impart an additional movement or oflset in accordance with and upon reversal of the direction of the rotation of the repeater motor, which of course takes place upon reversal in the direction of yaw of the ship or the craft. This additional movement is applied either to the trolleys or cams operated by the repeatenmotor, or to the otherwise stationary contact portion of the master controller.

The present case is a continuation of abandoned application Serial 110,215,282, filed June 22, 1938, for Automatic steering systems.

' One method of carrying this ,into effect is to" arrange a drag or slip friction connection 7 to solenoids, and the arm and the solenoids are connected to a source of supply of electricity. According, therefore, to the direction of rotation by the action of the solenoids. The direction of ll of motion of the ship changes.

rotation of the repeater.

Suppose that the ship has turned oil its course to starboard and the controller has applied rudder to check this turn. The turning movement of the ship slows down, stops. and reverses, asthe ship begins to return to its course. When f the repeater motor reverses its direction of motion the drag contact is dragged in the reverse direction to make the opposite contact. The stationary contacts are therefore quickly moved motion is arranged to be such as to take off a substantial amount of rudder. The result is that during the return of the ship to its course less rudder is used than in the corresponding stages of the ships departure from its course, so

N that, on the whole, energy is abstracted from the motion, and the side to side oscillation is damped. In the final stages of. the return'to the course, check rudder will even-be applied.

Adjustable stops may be fitted to limit, as reof the stationary contacts, and therefore limit the initial rudder movement when the direction Preferably these are arranged to adjust the additional movement to correspond to one or other integral multiple ofthe angular spacing between one of h the controller contacts and its neighbor.

engages with the side-of the contact ring remote 'of the repeaterthat is, according to the direction of turn or yaw of the ship-one or other of these solenoids will be energized, and will at-,

tract an armature in one direction or the other: Thearmature is mechanically connected to the contact ring, and therefore rotates this in ac- An alternative arrangement, which can be used if the repeater motor is suiiiciently powerful, is to arrange that the drag member, which,

in the system just described operated electric contacts to operate solenoids to turn the stationary contact ring, turns-the stationary ring directly. In order to obtain the correct direcabout a separate shaft, an extension of which from the shaft to rotate the contact ring when the gear quadrant is rotated. Alternatively, we niay'have the drag member itself mounted on a separate shaft whichis geared to turn with the shaft on the controller.

In any of these systems we prefer to that the additional movement or oflset given to the controller, e. g., to the contact rings (which causes initial rudder displacement) should die cordance with the directionof turn of the ship, away with time, i. e., with a decayed action. For

quired, the amount of this additional movement tion of operating, a reversing mechanism is required. One method of introducing reversal 7 is to use gearing. We arrange that the-drag member gears with a gear. quadrant turnable arrange 2 attains this' -purpose we may interpose a slowly leaking eter 82' may be energized from the D. C. device, such as a dash-pot, in the connection by instead of the potentiometer 92, the slider it which the additional movement is imparted, and i being simultaneously connected to the fleldWilh oppose the additional movement by'a centraliz 7 ing 9 of the generator d instead of the slider l6:

' ing spring arrangement lnitlally; the dash'pot "6 'thef'anriliary-potentiometer it therefore comdevice moves as a rigid member imparting the pietely replaces the imprinter-J2, The slider additional movement, but it is unable tomainit is operated by automatic m;which-wetain this displacement against the 'centralizlng-'- shall now describe, instead of by the steering force, so that the displacement gradually falls wheel iii. I

to zero in the absence of any further motion of W The potentiometer i2 operates as the master the controller due to turning of the ship. By or compass governed controller and it is shown this m ans, yaw s suppr d in a more fas being turned from the gyro com ass re eater fective manner than with the initial rudder or motor 55 which turns shaft i6. Shaft M is yaw anticipating devices of the priorart. even shown as connected through adjustable lost mein craft which are naturally unstable such as 313 tion device it, which is usually known as the high speed ships and aircraft, because when the weather yaw preventingueviee, to al shaft J8 p has returned to its original course no iniwhich operates one arm of the difierential it).

tial rudder is present to set up an incipient yaw. Another arm of said differential may be operated Referring to the drawings showing twoforms from the hand or trick steering wheel shown our invention may assume: as mounted on the e shaft as ar ar 26 Fig. 1 is a wiring diagram showing one form which turns the central arm 22 of the difierential r our invention. is. a locking handle as ma he provided so Fig. 2 is a diagramperspectiveview showing a that the repeater motor is locked when the lowdmodified form of the delayed action device of wheel, 2E9 is operated and vice verse; The drive Fig 1 13 from the hand wheel 20 operates through a slip Referring first to Fig. 1, the rudder i is shownfriction clutch 29. A third arm or said diderdriven through gearing 2 by an electric rudder ential enters change speed gear box 26 onmotor 3. The field winding of this motor is per-l crates shaft 66" through said gear, manently' excited from D. C. mains 8, and the) icon 23 which is operated from the gear shift ham armature is supplied from a Ward-leopard sendie 26. shaft 96" operates the controller slider erator 6 driven by a constantly running D. C- it. The gearretio selected in the gear icon 28 motor 5 supplied from the D. C. mains 3 through determines t angijmmed m h by the n,

a control panel 7, which 8,150 supplies the cur= de corresponding a, given deviation from rent for the field winding of the rudder motor 3. course, t et a t ay go The excitation current for the field winding of 33 that t handle mpg be termed th ad generator 3 is derived from an exoitergenerator 31 adju tment shaftqlg" gpamtigs 5, third shaft {3 whose g is conneci'fid t0 the Sudg6u0 there is thereon a ot ers it, Hot two potentiometers i2, i3. respmswe to h initial turning Potentiometer i2 i th co rotentiomeiefl V lneither direction. it; Etna? so is secured to shaft. it is called the wheel potentiometer since its slidid" to form an abutment for spring 35 which er it can be djusted by the steerin Wheel processes cone-faced clutch 32 keyed to shaft 06" Potentiometer i3 is the rudder potentiometer toward opposite cone raced clutch 83 fixed to its slider ii is actua e by the rudder shaft is". Pinion at is frictionally driven from so that it has a d fin 1105mm! mnespondmg said clutches by being provided with a wedge to each position of the rudder. Both potentiomsmiled under annular surmca said m' eters i2 and i re o nect d to the sefme D; gages rack teeth not shown on rack bar d! which supply t. a 1 i n The parts so far described constitute the usual gg gi 22 :252 azi g; 8.22%:

l form 0f electric Steering System 5% limited by an adjustable stop device comprising 7 while the field winding 9 of the exclter'generator tion is as follows; The two potentiometers It i and 93 may be considered as a Wheatstone bridge of which the supply mains form one diagonal,

- a block 39 with'a v-shaped cutawaypopflon 3 cured to the bar and a compiwentaryshaped 1 fired: stop id which may be adjusted t a d t 9 forms the other diagonal. If the bridge is by the adjusting screw 59 t y the 1 balanced there isno current in this winding. 56 gg i f motion Permitted the rack 38 I so that the generator d does not excite the gen- 5 t is-preversed in direction, mick will erato'r ii and motor 3 consequently does not run. m t0 the fun extent of itsrpossible OiiiOn so However,- if the balance of the bridge is upset, that block 39 l ton one side or the as for example, if the steering wheel H is turned, 9 the F The on 0f the rack the 'motor 3 runs and applies rudder. The motor bar 35 is imnsmitted t the sh f '6'" by the oes on running until the slider n reaches a new w rotatable c i or center rm 42 or the differposition on potentiometerit, corresponding to the ential but instead of employing a rigid link new position of slider 88 on potentiometer l2, between bs berth and the fiifie r we use a whereupon the motor 53 stops as the bridge is linkage containing'a in der to secure again balanced. this system there is no defi- 5 the decaying action above ed 150- nite indication Sin: the vicinity of the steering As Shown, a p fi cylinder 81 is pivoted on wheel M (i. e., on the bridge) of the position of h level 31 and a 986 fitting piston 38 therein jthe rudder. The position of slider H merely dej is linked to the difierential 62 by the piston rod "fines the position to which the rudder should so, h piston rod, and consequently the difler- 'drmay lac-considered a a, rudder ential M, are subjected to the action of a spring so at the ,Sli, ,5; r indi u; there is no rudder indicator as ra i i de ice This co pri es 1 111 0 on it ridge. piston rod 69 and two levers H, l2 pivoted at,

'In order to efiect automatic steering, we prothe former adapted to force the pin dods vide an auxiliary potentiometer i2 and a change- I if the pin should lift it upwards if the pin should over switch 5; so that theauxiliary potentiomdepress it off this stop. Both levers exert their ship has been turning anti-clockwise and that the corresponding direction of turning of shaft it" maintains the rack-35 in a downward position. If the ship ceases turning in the anti-clockwise direction and begins to turn in a clockwise directhe upward direction t the full distance permitted by the stop 39, giving an offset to the controller. The dashpot 61 will therefore be forced downwards and will take with it the piston-88,

since the motion is rapid: initially, therefore, the

differential casing 42 is rotated by an amount corresponding to the full permitted movement of the rack I5. However, the downward movement of the piston 88 and piston rod 69 depresses the lever "I2 from its stop 13 and extends the spring 14. o This spring exerts an upward force on the pin 10 throughout the whole time that the ship is turning clockwise, as a result of which the piston 88 slowly moves upwards in the dashpot until the pin III is in its central or zero position again. In

order that this rate of movement may be regulated as desired, a pipe connection may be provided between the ends of the dashpot cylinder with an adjustable valve 16 for varying the constric- .tion therebetween. Thus, the system operates to restore the arm 42 slowly towards its normal or zero position, after it has been moved therefrom as a result of a change in the direction of turn of the ship.

The motion of center arm 42 of differential 43 is superimposed on the motion of shaft l B" to operate shaft IG', which operates a controller controlling the steering of the ship. This controller is shown in the form of a circular rheostat, with contact studs 45 arranged in a circle with their inner faces concentric with the axis of rotation of the contact-arm Hi. On this arm are pivoted two levers 41, 41 each of which is spring conaway or decayed action in the lost motion device. Inthis case, the friction drag pinion 34 is replaced wby slip-friction or friction dragarm 34' having a frictional connection to the shaft It" so that said arm is oscillated between fixed stops 85 and II upon eachreversal in the direction of rotation in the shaft I6". This motion of the armacts to close one or the other of the -pairs of contacts 81 and" so as to energize solenoid 89 or 8B, respectively. The energized solenoid attracts an armaq tigre which is in the form of a lever 9| pivoted at l An adjustable stop device 93 may be provided whereby the amount of movement permitted to the lever 9| may be limited; This constitutes a modified form of initial rudder adjustment. The far end of the lever is shown as connected to the planetary arm or ring 42 of the differential 43 which as before, operates between shaft l6 and 0'' to actuate the master controller 46 such as shown. in Fig. 1. The linkage between the lever 8i and the planetary arm 42 is shown as con- The system of Fig. 2 operates the steering controller, i. e, operates shaft W." in almost exactly the same manner as does the system of Fig. 1, for the movement imparted to planetary arm 42, is in both cases due to the movement-of the friction drag member (by gear 34 or arm 34'), the main difl'erence being that inFig. 1 the operation is by direct mechanical means, whereas in Fig. 2 an electro-mechanical relay is employed. While the use of a relay introduces an additional, mechation,.the rack 35 will immediately move rapidly-in l0 nism, it has advantages since the system of Fig. 1 has to be rather nicely adjusted throughout with respect to friction and other loadings, whereas the system of Fig. 2 is more robust.

From the foregoing it is believed that the operation of our invention will be apparent and the advantages thereof overthe prior art yaw-preventing or-initial rudder" devices. In the prior art devices, as reprsented in said Sperry patent, the initial rudder, once applied, remains until the ship reverses its direction of. yaw when it is reversed. In applicant's device, on the other hand, by reason of the self-centralizing dashpot the lost motion is gradually eliminated and the rudder is always brought back to its mid position afteran interval so that, upon a new yaw in either direction, the initial rudder will be brought into play immediately in the proper direction. In other words, in the prior systems a certain amount of initial rudder usually remains by the time the ship gets back to course, thus tending to set up another yaw, while in applicant's case the initial rudder is substantially removed by this time, thus removing one cause of yawing. It will also be obvious that in its broad aspects our invention is adaptable to all lost motion type yaw suppressors. whether incorporated in a, Ward-Leonard type of follower-back or in a mechanical type followback of the prior art, in which the lost motion is usually supplied within the follow-back connection itself, as shown in siad Sperry patent. v

It is also apparent that by suitable adjustments of the tension of spring 14 and/or the rate of leak through the piston 68 in the dashpot cylinder, the rate of elimination of the initial rudder may be varied to suit the needs of the individual craft. In fact, this rate may be adjusted so that the initial rudder is not completelyremoved until the ship has passed its original course and is about to change its direction of yaw, if desired. If any initial rudder remains at this time, it will of course be removed and initial rudder applied in the opposite direction upon reversal of yaw.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be made without departing from the scope thereof, it

60 ings shall be interpreted as illustrative and not in a limiting sense.

Having-described our invention, what, we claim and desire to secure by Letters Patent is:

1. In an automatic steering device for craft, a controller the relative position of which is primarily governed by the heading of the craft .with respect to the compass, a rudder servo motor actuated therefrom, additional means responsive to a change in the direction of yaw of the craft to give said controller an offset to impart an ini-- tial rudder movement to said servo motor; and means for decreasing said ofiset toreduce said initial movement as the craft returns to its course.

2. In an automatic steering device for craft, a controller the relative position of which is pri- 4L mevllv governed by the needles of the crest with respect to the compass, a welder servo motor actuated therefrom, end ecldltlo means se sponsive to e cheese in' the direction of yew of the ship to giveselel controller an offset to import an initial rudder movemetat to said servo motor, including a, llmtzeeesystem end a spring centrelized deshgtot therein Tees 2. slow leek, whereby said ofi'eet is eretluellv reduced ass-tine craft returns to its course.

3. In em out/emetic steering device for craft, e controller the relative meltiou of which is pri metlly governetilov the heading off the creft'wlth icesuect to the compass, o, rudder servo motor ectueteel therefrom, and eoclitionel means resconsive to e chezoge in the direction of yew of the craft to give ssicl controller en oflset to lm pelt an initial model" movement to said motor, including e. memlsev oscillated as short distance upon cheege in tllreetiou of yew of the craft, electricel contacts eflepteol to lee closed by selcl member at eeclt end of its oscillation, magnetic mesns alternately enemizetlthereby to oscillate on emluture, and e storms centralized slow leels (lesh ot connected between eeld armature end seidcozltroller, whereby sold ofiset is reduced as the craft returns to course.

4. In on automatic steering 5 12,1 tor dirigiblebudge circuit and ectus upon revei'sel in the direction of your of the craft tor supe 11-1 on the rudder 'movemeutlmposed by the compess e further movement ofu -w ted gmtutle in one direction or the other in accordance with the directlon in which the o is vewme, time means for causing said further adjustment imposed by said initial rudder device to be substantially reduced before the omit reverses its direction of yew. I

5. In an automatic steering device Ker craft, e controllerthe relative postticel of which is pri= merily governed by the heading of the omit with respect to s compass, at rudder servo motor actuated therefrom, and. eclditicuel meens resgoonsive to a. change in the dii ectlou of you of the craft to give said controller; an ofiset to import on initial model-"movement to sold servo motor, said means including e tlmeoi cleceviug'devlce interposed between sslcl meees end solo conttoiler. whereby the effect of meeus is slowly reduced to zero after each inltiel'x'uclder movement.

6. In an automotic steexins olevtce for craft a controller the reletive pcsltiozx of which isprlmarily gove by the heme of the craft with decreasing said ofieet to refiuce eeld lnltlel movement as the emit returns-to its course, and means Geog-seem SAUL. v GEQRGE BERT 

